bug 887819 - Investigate using the tiled layers backend, create pref to enable tiles r=BenWa

b2g/app/b2g.js

@@ -73,6 +73,7 @@ pref("mozilla.widget.force-24bpp", true);
 pref("mozilla.widget.use-buffer-pixmap", true);
 pref("mozilla.widget.disable-native-theme", true);
 pref("layout.reflow.synthMouseMove", false);
+pref("layers.force-tiles", false);
 
 /* download manager (don't show the window or alert) */
 pref("browser.download.useDownloadDir", true);

gfx/layers/TiledLayerBuffer.h

@@ -7,11 +7,6 @@
 
 #define TILEDLAYERBUFFER_TILE_SIZE 256
 
-#ifdef MOZ_ANDROID_OMTC
-  // This needs to go away as we enabled tiled
-  // layers everywhere.
-  #define FORCE_BASICTILEDTHEBESLAYER
-#endif
 // Debug defines
 //#define GFX_TILEDLAYER_DEBUG_OVERLAY
 //#define GFX_TILEDLAYER_PREF_WARNINGS

gfx/layers/client/ClientThebesLayer.cpp

@@ -17,6 +17,7 @@
 #include "mozilla/gfx/Rect.h"           // for Rect, IntRect
 #include "mozilla/gfx/Types.h"          // for Float, etc
 #include "mozilla/layers/LayersTypes.h"
+#include "mozilla/Preferences.h"
 #include "nsAutoPtr.h"                  // for nsRefPtr
 #include "nsCOMPtr.h"                   // for already_AddRefed
 #include "nsISupportsImpl.h"            // for Layer::AddRef, etc
@@ -185,14 +186,12 @@ already_AddRefed<ThebesLayer>
 ClientLayerManager::CreateThebesLayer()
 {
   NS_ASSERTION(InConstruction(), "Only allowed in construction phase");
-#ifdef FORCE_BASICTILEDTHEBESLAYER
-  if (GetCompositorBackendType() == LAYERS_OPENGL) {
+  if (Preferences::GetBool("layers.force-tiles") && GetCompositorBackendType() == LAYERS_OPENGL) {
     nsRefPtr<ClientTiledThebesLayer> layer =
       new ClientTiledThebesLayer(this);
     CREATE_SHADOW(Thebes);
     return layer.forget();
   } else
-#endif
   {
     nsRefPtr<ClientThebesLayer> layer =
       new ClientThebesLayer(this);

mobile/android/app/mobile.js

@@ -718,6 +718,8 @@ pref("memory.free_dirty_pages", true);
 
 pref("layout.imagevisibility.enabled", false);
 
+pref("layers.force-tiles", true);
+
 // Enable the dynamic toolbar
 pref("browser.chrome.dynamictoolbar", true);