diff --git a/gfx/webrender_bindings/revision.txt b/gfx/webrender_bindings/revision.txt
index fd0df131585f..f71364c4eaeb 100644
--- a/gfx/webrender_bindings/revision.txt
+++ b/gfx/webrender_bindings/revision.txt
@@ -1 +1 @@
-57379d1fec269ea70cbab28d4353614fd9c58122
+6bdd0d26afe3fc5a24f10c19d4ca8569d0182a37
diff --git a/gfx/wr/examples/common/boilerplate.rs b/gfx/wr/examples/common/boilerplate.rs
index 1924cf6125f3..a5a2b8401536 100644
--- a/gfx/wr/examples/common/boilerplate.rs
+++ b/gfx/wr/examples/common/boilerplate.rs
@@ -11,6 +11,7 @@ use std::env;
 use std::path::PathBuf;
 use webrender;
 use winit;
+use webrender::DebugFlags;
 use webrender::ShaderPrecacheFlags;
 use webrender::api::*;
 
@@ -147,13 +148,14 @@ pub fn main_wrapper<E: Example>(
     println!("Device pixel ratio: {}", device_pixel_ratio);
 
     println!("Loading shaders...");
+    let mut debug_flags = DebugFlags::ECHO_DRIVER_MESSAGES | DebugFlags::TEXTURE_CACHE_DBG;
     let opts = webrender::RendererOptions {
         resource_override_path: res_path,
         precache_flags: E::PRECACHE_SHADER_FLAGS,
         device_pixel_ratio,
         clear_color: Some(ColorF::new(0.3, 0.0, 0.0, 1.0)),
         //scatter_gpu_cache_updates: false,
-        debug_flags: webrender::DebugFlags::ECHO_DRIVER_MESSAGES,
+        debug_flags,
         ..options.unwrap_or(webrender::RendererOptions::default())
     };
 
@@ -179,8 +181,6 @@ pub fn main_wrapper<E: Example>(
         renderer.set_external_image_handler(external_image_handler);
     }
 
-    renderer.toggle_debug_flags(webrender::DebugFlags::TEXTURE_CACHE_DBG);
-
     let epoch = Epoch(0);
     let pipeline_id = PipelineId(0, 0);
     let layout_size = framebuffer_size.to_f32() / euclid::TypedScale::new(device_pixel_ratio);
@@ -211,6 +211,7 @@ pub fn main_wrapper<E: Example>(
         let mut txn = Transaction::new();
         let mut custom_event = true;
 
+        let old_flags = debug_flags;
         match global_event {
             winit::Event::WindowEvent {
                 event: winit::WindowEvent::CloseRequested,
@@ -228,22 +229,17 @@ pub fn main_wrapper<E: Example>(
                 ..
             } => match key {
                 winit::VirtualKeyCode::Escape => return winit::ControlFlow::Break,
-                winit::VirtualKeyCode::P => renderer.toggle_debug_flags(webrender::DebugFlags::PROFILER_DBG),
-                winit::VirtualKeyCode::O => renderer.toggle_debug_flags(webrender::DebugFlags::RENDER_TARGET_DBG),
-                winit::VirtualKeyCode::I => renderer.toggle_debug_flags(webrender::DebugFlags::TEXTURE_CACHE_DBG),
-                winit::VirtualKeyCode::S => renderer.toggle_debug_flags(webrender::DebugFlags::COMPACT_PROFILER),
-                winit::VirtualKeyCode::Q => renderer.toggle_debug_flags(
-                    webrender::DebugFlags::GPU_TIME_QUERIES | webrender::DebugFlags::GPU_SAMPLE_QUERIES
+                winit::VirtualKeyCode::P => debug_flags.toggle(DebugFlags::PROFILER_DBG),
+                winit::VirtualKeyCode::O => debug_flags.toggle(DebugFlags::RENDER_TARGET_DBG),
+                winit::VirtualKeyCode::I => debug_flags.toggle(DebugFlags::TEXTURE_CACHE_DBG),
+                winit::VirtualKeyCode::S => debug_flags.toggle(DebugFlags::COMPACT_PROFILER),
+                winit::VirtualKeyCode::Q => debug_flags.toggle(
+                    DebugFlags::GPU_TIME_QUERIES | DebugFlags::GPU_SAMPLE_QUERIES
                 ),
-                winit::VirtualKeyCode::F => renderer.toggle_debug_flags(
-                    webrender::DebugFlags::NEW_FRAME_INDICATOR | webrender::DebugFlags::NEW_SCENE_INDICATOR
-                ),
-                winit::VirtualKeyCode::G => api.send_debug_cmd(
-                    // go through the API so that we reach the render backend
-                    DebugCommand::EnableGpuCacheDebug(
-                        !renderer.get_debug_flags().contains(webrender::DebugFlags::GPU_CACHE_DBG)
-                    ),
+                winit::VirtualKeyCode::F => debug_flags.toggle(
+                    DebugFlags::NEW_FRAME_INDICATOR | DebugFlags::NEW_SCENE_INDICATOR
                 ),
+                winit::VirtualKeyCode::G => debug_flags.toggle(DebugFlags::GPU_CACHE_DBG),
                 winit::VirtualKeyCode::Key1 => txn.set_window_parameters(
                     framebuffer_size,
                     DeviceIntRect::new(DeviceIntPoint::zero(), framebuffer_size),
@@ -282,6 +278,10 @@ pub fn main_wrapper<E: Example>(
             _ => return winit::ControlFlow::Continue,
         };
 
+        if debug_flags != old_flags {
+            api.send_debug_cmd(DebugCommand::SetFlags(debug_flags));
+        }
+
         if custom_event {
             let mut builder = DisplayListBuilder::new(pipeline_id, layout_size);
 
diff --git a/gfx/wr/examples/multiwindow.rs b/gfx/wr/examples/multiwindow.rs
index 0e92bcb34cc8..9b2df6d7b5ad 100644
--- a/gfx/wr/examples/multiwindow.rs
+++ b/gfx/wr/examples/multiwindow.rs
@@ -15,6 +15,7 @@ use glutin::GlContext;
 use std::fs::File;
 use std::io::Read;
 use webrender::api::*;
+use webrender::DebugFlags;
 use winit::dpi::LogicalSize;
 
 struct Notifier {
@@ -142,6 +143,7 @@ impl Window {
         let mut do_exit = false;
         let my_name = &self.name;
         let renderer = &mut self.renderer;
+        let api = &mut self.api;
 
         self.events_loop.poll_events(|global_event| match global_event {
             winit::Event::WindowEvent { event, .. } => match event {
@@ -163,8 +165,8 @@ impl Window {
                     },
                     ..
                 } => {
-                    println!("toggle flags {}", my_name);
-                    renderer.toggle_debug_flags(webrender::DebugFlags::PROFILER_DBG);
+                    println!("set flags {}", my_name);
+                    api.send_debug_cmd(DebugCommand::SetFlags(DebugFlags::PROFILER_DBG))
                 }
                 _ => {}
             }
@@ -278,7 +280,7 @@ impl Window {
         );
         txn.set_root_pipeline(self.pipeline_id);
         txn.generate_frame();
-        self.api.send_transaction(self.document_id, txn);
+        api.send_transaction(self.document_id, txn);
 
         renderer.update();
         renderer.render(framebuffer_size).unwrap();
diff --git a/gfx/wr/webrender/src/debug_server.rs b/gfx/wr/webrender/src/debug_server.rs
index 4371c9922e9a..02d302630008 100644
--- a/gfx/wr/webrender/src/debug_server.rs
+++ b/gfx/wr/webrender/src/debug_server.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use api::{ApiMsg, DebugCommand, DeviceIntSize};
+use api::{ApiMsg, DebugCommand, DebugFlags, DeviceIntSize};
 use api::channel::MsgSender;
 use print_tree::PrintTreePrinter;
 use std::sync::mpsc::{channel, Receiver};
@@ -26,6 +26,7 @@ struct Server {
     ws: ws::Sender,
     debug_tx: Sender<DebugMsg>,
     api_tx: MsgSender<ApiMsg>,
+    debug_flags: DebugFlags,
 }
 
 impl ws::Handler for Server {
@@ -46,25 +47,35 @@ impl ws::Handler for Server {
     fn on_message(&mut self, msg: ws::Message) -> ws::Result<()> {
         match msg {
             ws::Message::Text(string) => {
-                let cmd = match string.as_str() {
-                    "enable_profiler" => DebugCommand::EnableProfiler(true),
-                    "disable_profiler" => DebugCommand::EnableProfiler(false),
-                    "enable_texture_cache_debug" => DebugCommand::EnableTextureCacheDebug(true),
-                    "disable_texture_cache_debug" => DebugCommand::EnableTextureCacheDebug(false),
-                    "enable_render_target_debug" => DebugCommand::EnableRenderTargetDebug(true),
-                    "disable_render_target_debug" => DebugCommand::EnableRenderTargetDebug(false),
-                    "enable_gpu_time_queries" => DebugCommand::EnableGpuTimeQueries(true),
-                    "disable_gpu_time_queries" => DebugCommand::EnableGpuTimeQueries(false),
-                    "enable_gpu_sample_queries" => DebugCommand::EnableGpuSampleQueries(true),
-                    "disable_gpu_sample_queries" => DebugCommand::EnableGpuSampleQueries(false),
-                    "fetch_passes" => DebugCommand::FetchPasses,
-                    "fetch_screenshot" => DebugCommand::FetchScreenshot,
-                    "fetch_documents" => DebugCommand::FetchDocuments,
-                    "fetch_clip_scroll_tree" => DebugCommand::FetchClipScrollTree,
-                    "fetch_render_tasks" => DebugCommand::FetchRenderTasks,
-                    msg => {
-                        error!("unknown msg {}", msg);
-                        return Ok(());
+                // First, check for flag change commands.
+                let mut set_flags = true;
+                match string.as_str() {
+                    "enable_profiler" => self.debug_flags.insert(DebugFlags::PROFILER_DBG),
+                    "disable_profiler" => self.debug_flags.remove(DebugFlags::PROFILER_DBG),
+                    "enable_texture_cache_debug" => self.debug_flags.insert(DebugFlags::TEXTURE_CACHE_DBG),
+                    "disable_texture_cache_debug" => self.debug_flags.remove(DebugFlags::TEXTURE_CACHE_DBG),
+                    "enable_render_target_debug" => self.debug_flags.insert(DebugFlags::RENDER_TARGET_DBG),
+                    "disable_render_target_debug" => self.debug_flags.remove(DebugFlags::RENDER_TARGET_DBG),
+                    "enable_gpu_time_queries" => self.debug_flags.insert(DebugFlags::GPU_TIME_QUERIES),
+                    "disable_gpu_time_queries" => self.debug_flags.remove(DebugFlags::GPU_TIME_QUERIES),
+                    "enable_gpu_sample_queries" => self.debug_flags.insert(DebugFlags::GPU_SAMPLE_QUERIES),
+                    "disable_gpu_sample_queries" => self.debug_flags.remove(DebugFlags::GPU_SAMPLE_QUERIES),
+                    _ => set_flags = false,
+                };
+
+                let cmd = if set_flags {
+                    DebugCommand::SetFlags(self.debug_flags)
+                } else {
+                    match string.as_str() {
+                        "fetch_passes" => DebugCommand::FetchPasses,
+                        "fetch_screenshot" => DebugCommand::FetchScreenshot,
+                        "fetch_documents" => DebugCommand::FetchDocuments,
+                        "fetch_clip_scroll_tree" => DebugCommand::FetchClipScrollTree,
+                        "fetch_render_tasks" => DebugCommand::FetchRenderTasks,
+                        msg => {
+                            error!("unknown msg {}", msg);
+                            return Ok(());
+                        }
                     }
                 };
 
@@ -97,6 +108,7 @@ impl DebugServer {
                     ws: out,
                     debug_tx: debug_tx.clone(),
                     api_tx: api_tx.clone(),
+                    debug_flags: DebugFlags::empty(),
                 }
             })
             .unwrap();
diff --git a/gfx/wr/webrender/src/gpu_cache.rs b/gfx/wr/webrender/src/gpu_cache.rs
index 5d1d79fd4822..be9bdee35f59 100644
--- a/gfx/wr/webrender/src/gpu_cache.rs
+++ b/gfx/wr/webrender/src/gpu_cache.rs
@@ -24,7 +24,7 @@
 //! address in the GPU cache of a given resource slot
 //! for this frame.
 
-use api::{PremultipliedColorF, TexelRect};
+use api::{DebugFlags, PremultipliedColorF, TexelRect};
 use api::{VoidPtrToSizeFn};
 use euclid::TypedRect;
 use profiler::GpuCacheProfileCounters;
@@ -234,7 +234,6 @@ pub enum GpuCacheUpdate {
 
 pub struct GpuDebugChunk {
     pub address: GpuCacheAddress,
-    pub fresh: bool,
     pub tag: u8,
     pub size: u16,
 }
@@ -541,9 +540,8 @@ pub struct GpuCache {
     /// Number of blocks requested this frame that don't
     /// need to be re-uploaded.
     saved_block_count: usize,
-    /// True if the Renderer expects to receive the metadata
-    /// about GPU blocks with on each update.
-    in_debug: bool,
+    /// The current debug flags for the system.
+    debug_flags: DebugFlags,
 }
 
 impl GpuCache {
@@ -552,7 +550,7 @@ impl GpuCache {
             frame_id: FrameId::INVALID,
             texture: Texture::new(),
             saved_block_count: 0,
-            in_debug: false,
+            debug_flags: DebugFlags::empty(),
         }
     }
 
@@ -653,13 +651,12 @@ impl GpuCache {
         GpuCacheUpdateList {
             frame_id: self.frame_id,
             height: self.texture.height,
-            debug_chunks: if self.in_debug {
+            debug_chunks: if self.debug_flags.contains(DebugFlags::GPU_CACHE_DBG) {
                 self.texture.updates
                     .iter()
                     .map(|update| match *update {
-                        GpuCacheUpdate::Copy { address, block_index, block_count } => GpuDebugChunk {
+                        GpuCacheUpdate::Copy { address, block_index: _, block_count } => GpuDebugChunk {
                             address,
-                            fresh: self.frame_id == self.texture.blocks[block_index].last_access_time,
                             tag: 0, //TODO
                             size: block_count.min(0xFFFF) as u16,
                         }
@@ -673,9 +670,9 @@ impl GpuCache {
         }
     }
 
-    /// Enable GPU block debugging.
-    pub fn set_debug(&mut self, enable: bool) {
-        self.in_debug = enable;
+    /// Sets the current debug flags for the system.
+    pub fn set_debug_flags(&mut self, flags: DebugFlags) {
+        self.debug_flags = flags;
     }
 
     /// Get the actual GPU address in the texture for a given slot ID.
diff --git a/gfx/wr/webrender/src/render_backend.rs b/gfx/wr/webrender/src/render_backend.rs
index 35d2192748de..143adf89cdc1 100644
--- a/gfx/wr/webrender/src/render_backend.rs
+++ b/gfx/wr/webrender/src/render_backend.rs
@@ -17,7 +17,7 @@ use api::{IdNamespace, LayoutPoint, PipelineId, RenderNotifier, SceneMsg, Scroll
 use api::{MemoryReport, VoidPtrToSizeFn};
 use api::{ScrollLocation, ScrollNodeState, TransactionMsg, ResourceUpdate, BlobImageKey};
 use api::{NotificationRequest, Checkpoint};
-use api::channel::{MsgReceiver, Payload};
+use api::channel::{MsgReceiver, MsgSender, Payload};
 #[cfg(feature = "capture")]
 use api::CaptureBits;
 #[cfg(feature = "replay")]
@@ -1031,10 +1031,6 @@ impl RenderBackend {
                         // We don't want to forward this message to the renderer.
                         return true;
                     }
-                    DebugCommand::EnableGpuCacheDebug(enable) => {
-                        self.gpu_cache.set_debug(enable);
-                        ResultMsg::DebugCommand(option)
-                    }
                     DebugCommand::FetchDocuments => {
                         let json = self.get_docs_for_debugger();
                         ResultMsg::DebugOutput(DebugOutput::FetchDocuments(json))
@@ -1107,6 +1103,7 @@ impl RenderBackend {
                     }
                     DebugCommand::SetFlags(flags) => {
                         self.resource_cache.set_debug_flags(flags);
+                        self.gpu_cache.set_debug_flags(flags);
                         ResultMsg::DebugCommand(option)
                     }
                     _ => ResultMsg::DebugCommand(option),
@@ -1502,7 +1499,7 @@ impl RenderBackend {
         serde_json::to_string(&debug_root).unwrap()
     }
 
-    fn report_memory(&self, tx: ::api::channel::MsgSender<MemoryReport>) {
+    fn report_memory(&self, tx: MsgSender<MemoryReport>) {
         let mut report = MemoryReport::default();
         let op = self.size_of_op.unwrap();
         report.gpu_cache_metadata = self.gpu_cache.malloc_size_of(op);
diff --git a/gfx/wr/webrender/src/renderer.rs b/gfx/wr/webrender/src/renderer.rs
index fba3297bb357..0f9f271d30c9 100644
--- a/gfx/wr/webrender/src/renderer.rs
+++ b/gfx/wr/webrender/src/renderer.rs
@@ -2384,33 +2384,6 @@ impl Renderer {
 
     fn handle_debug_command(&mut self, command: DebugCommand) {
         match command {
-            DebugCommand::EnableProfiler(enable) => {
-                self.set_debug_flag(DebugFlags::PROFILER_DBG, enable);
-            }
-            DebugCommand::EnableTextureCacheDebug(enable) => {
-                self.set_debug_flag(DebugFlags::TEXTURE_CACHE_DBG, enable);
-            }
-            DebugCommand::EnableRenderTargetDebug(enable) => {
-                self.set_debug_flag(DebugFlags::RENDER_TARGET_DBG, enable);
-            }
-            DebugCommand::EnableGpuCacheDebug(enable) => {
-                self.set_debug_flag(DebugFlags::GPU_CACHE_DBG, enable);
-            }
-            DebugCommand::EnableGpuTimeQueries(enable) => {
-                self.set_debug_flag(DebugFlags::GPU_TIME_QUERIES, enable);
-            }
-            DebugCommand::EnableGpuSampleQueries(enable) => {
-                self.set_debug_flag(DebugFlags::GPU_SAMPLE_QUERIES, enable);
-            }
-            DebugCommand::EnableNewFrameIndicator(enable) => {
-                self.set_debug_flag(DebugFlags::NEW_FRAME_INDICATOR, enable);
-            }
-            DebugCommand::EnableNewSceneIndicator(enable) => {
-                self.set_debug_flag(DebugFlags::NEW_SCENE_INDICATOR, enable);
-            }
-            DebugCommand::EnableShowOverdraw(enable) => {
-                self.set_debug_flag(DebugFlags::SHOW_OVERDRAW, enable);
-            }
             DebugCommand::EnableDualSourceBlending(_) => {
                 panic!("Should be handled by render backend");
             }
@@ -4257,18 +4230,6 @@ impl Renderer {
         self.debug_flags = flags;
     }
 
-    pub fn set_debug_flag(&mut self, flag: DebugFlags, enabled: bool) {
-        let mut new_flags = self.debug_flags;
-        new_flags.set(flag, enabled);
-        self.set_debug_flags(new_flags);
-    }
-
-    pub fn toggle_debug_flags(&mut self, toggle: DebugFlags) {
-        let mut new_flags = self.debug_flags;
-        new_flags.toggle(toggle);
-        self.set_debug_flags(new_flags);
-    }
-
     pub fn save_cpu_profile(&self, filename: &str) {
         write_profile(filename);
     }
diff --git a/gfx/wr/webrender/src/scene_builder.rs b/gfx/wr/webrender/src/scene_builder.rs
index c8585729685f..872a7d0fbfa2 100644
--- a/gfx/wr/webrender/src/scene_builder.rs
+++ b/gfx/wr/webrender/src/scene_builder.rs
@@ -169,7 +169,7 @@ pub enum SceneBuilderRequest {
     SimulateLongSceneBuild(u32),
     SimulateLongLowPrioritySceneBuild(u32),
     Stop,
-    ReportMemory(MemoryReport, ::api::channel::MsgSender<MemoryReport>),
+    ReportMemory(MemoryReport, MsgSender<MemoryReport>),
     #[cfg(feature = "capture")]
     SaveScene(CaptureConfig),
     #[cfg(feature = "replay")]
diff --git a/gfx/wr/webrender_api/src/api.rs b/gfx/wr/webrender_api/src/api.rs
index f8049be2fc26..de0bac65556d 100644
--- a/gfx/wr/webrender_api/src/api.rs
+++ b/gfx/wr/webrender_api/src/api.rs
@@ -680,26 +680,10 @@ pub struct CapturedDocument {
 
 #[derive(Clone, Deserialize, Serialize)]
 pub enum DebugCommand {
-    /// Display the frame profiler on screen.
-    EnableProfiler(bool),
-    /// Display all texture cache pages on screen.
-    EnableTextureCacheDebug(bool),
-    /// Display intermediate render targets on screen.
-    EnableRenderTargetDebug(bool),
-    /// Display the contents of GPU cache.
-    EnableGpuCacheDebug(bool),
-    /// Display GPU timing results.
-    EnableGpuTimeQueries(bool),
-    /// Display GPU overdraw results
-    EnableGpuSampleQueries(bool),
+    /// Sets the provided debug flags.
+    SetFlags(DebugFlags),
     /// Configure if dual-source blending is used, if available.
     EnableDualSourceBlending(bool),
-    /// Show an indicator that moves every time a frame is rendered.
-    EnableNewFrameIndicator(bool),
-    /// Show an indicator that moves every time a scene is built.
-    EnableNewSceneIndicator(bool),
-    /// Show an overlay displaying overdraw amount.
-    EnableShowOverdraw(bool),
     /// Fetch current documents and display lists.
     FetchDocuments,
     /// Fetch current passes and batches.
@@ -724,9 +708,6 @@ pub enum DebugCommand {
     /// Causes the low priority scene builder to pause for a given amount of miliseconds
     /// each time it processes a transaction.
     SimulateLongLowPrioritySceneBuild(u32),
-    /// Sets the provided debug flags. This may overlap with some of the functionality
-    /// above.
-    SetFlags(DebugFlags),
 }
 
 #[derive(Clone, Deserialize, Serialize)]
@@ -980,18 +961,26 @@ impl RenderApiSender {
 bitflags! {
     #[derive(Default, Deserialize, Serialize)]
     pub struct DebugFlags: u32 {
+        /// Display the frame profiler on screen.
         const PROFILER_DBG          = 1 << 0;
+        /// Display intermediate render targets on screen.
         const RENDER_TARGET_DBG     = 1 << 1;
+        /// Display all texture cache pages on screen.
         const TEXTURE_CACHE_DBG     = 1 << 2;
+        /// Display GPU timing results.
         const GPU_TIME_QUERIES      = 1 << 3;
         const GPU_SAMPLE_QUERIES    = 1 << 4;
         const DISABLE_BATCHING      = 1 << 5;
         const EPOCHS                = 1 << 6;
         const COMPACT_PROFILER      = 1 << 7;
         const ECHO_DRIVER_MESSAGES  = 1 << 8;
+        /// Show an indicator that moves every time a frame is rendered.
         const NEW_FRAME_INDICATOR   = 1 << 9;
+        /// Show an indicator that moves every time a scene is built.
         const NEW_SCENE_INDICATOR   = 1 << 10;
+        /// Show an overlay displaying overdraw amount.
         const SHOW_OVERDRAW         = 1 << 11;
+        /// Display the contents of GPU cache.
         const GPU_CACHE_DBG         = 1 << 12;
         const SLOW_FRAME_INDICATOR  = 1 << 13;
         const TEXTURE_CACHE_DBG_CLEAR_EVICTED = 1 << 14;
diff --git a/gfx/wr/wrench/src/main.rs b/gfx/wr/wrench/src/main.rs
index f412233aef41..82cdd10bdbcb 100644
--- a/gfx/wr/wrench/src/main.rs
+++ b/gfx/wr/wrench/src/main.rs
@@ -565,6 +565,7 @@ fn render<'a>(
     wrench.update(dim);
     thing.do_frame(wrench);
 
+    let mut debug_flags = DebugFlags::empty();
     let mut body = |wrench: &mut Wrench, global_event: winit::Event| {
         let mut do_frame = false;
         let mut do_render = false;
@@ -597,36 +598,39 @@ fn render<'a>(
                         return winit::ControlFlow::Break;
                     }
                     VirtualKeyCode::P => {
-                        wrench.renderer.toggle_debug_flags(DebugFlags::PROFILER_DBG);
+                        debug_flags.toggle(DebugFlags::PROFILER_DBG);
+                        wrench.api.send_debug_cmd(DebugCommand::SetFlags(debug_flags));
                         do_render = true;
                     }
                     VirtualKeyCode::O => {
-                        wrench.renderer.toggle_debug_flags(DebugFlags::RENDER_TARGET_DBG);
+                        debug_flags.toggle(DebugFlags::RENDER_TARGET_DBG);
+                        wrench.api.send_debug_cmd(DebugCommand::SetFlags(debug_flags));
                         do_render = true;
                     }
                     VirtualKeyCode::I => {
-                        wrench.renderer.toggle_debug_flags(DebugFlags::TEXTURE_CACHE_DBG);
+                        debug_flags.toggle(DebugFlags::TEXTURE_CACHE_DBG);
+                        wrench.api.send_debug_cmd(DebugCommand::SetFlags(debug_flags));
                         do_render = true;
                     }
                     VirtualKeyCode::S => {
-                        wrench.renderer.toggle_debug_flags(DebugFlags::COMPACT_PROFILER);
+                        debug_flags.toggle(DebugFlags::COMPACT_PROFILER);
+                        wrench.api.send_debug_cmd(DebugCommand::SetFlags(debug_flags));
                         do_render = true;
                     }
                     VirtualKeyCode::Q => {
-                        wrench.renderer.toggle_debug_flags(
-                            DebugFlags::GPU_TIME_QUERIES | DebugFlags::GPU_SAMPLE_QUERIES
-                        );
+                        debug_flags.toggle(DebugFlags::GPU_TIME_QUERIES | DebugFlags::GPU_SAMPLE_QUERIES);
+                        wrench.api.send_debug_cmd(DebugCommand::SetFlags(debug_flags));
                         do_render = true;
                     }
                     VirtualKeyCode::V => {
-                        wrench.renderer.toggle_debug_flags(DebugFlags::SHOW_OVERDRAW);
+                        debug_flags.toggle(DebugFlags::SHOW_OVERDRAW);
+                        wrench.api.send_debug_cmd(DebugCommand::SetFlags(debug_flags));
                         do_render = true;
                     }
                     VirtualKeyCode::G => {
-                        // go through the API so that we reach the render backend
-                        wrench.api.send_debug_cmd(DebugCommand::EnableGpuCacheDebug(
-                            !wrench.renderer.get_debug_flags().contains(webrender::DebugFlags::GPU_CACHE_DBG)
-                        ));
+                        debug_flags.toggle(DebugFlags::GPU_CACHE_DBG);
+                        wrench.api.send_debug_cmd(DebugCommand::SetFlags(debug_flags));
+
                         // force scene rebuild to see the full set of used GPU cache entries
                         let mut txn = Transaction::new();
                         txn.set_root_pipeline(wrench.root_pipeline_id);