perf: avoid redundant calls to GetView() (#43230)

* perf: avoid double-calls to GetView()

There are a lot of places where we call the virtual method GetView()
twice in succession: the first to check if the view exists, and the
second to use. This PR holds the view in a temp variable instead, e.g.:

if (auto* view = foo->GetView())
  view->DoSomething();

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* perf: avoid discarded GetView() call

Co-authored-by: Charles Kerr <charles@charleskerr.com>

---------

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>

shell/browser/api/frame_subscriber.cc

@@ -37,13 +37,14 @@ void FrameSubscriber::AttachToHost(content::RenderWidgetHost* host) {
 
   // The view can be null if the renderer process has crashed.
   // (https://crbug.com/847363)
-  if (!host_->GetView())
+  auto* rwhv = host_->GetView();
+  if (!rwhv)
     return;
 
   // Create and configure the video capturer.
   gfx::Size size = GetRenderViewSize();
   DCHECK(!size.IsEmpty());
-  video_capturer_ = host_->GetView()->CreateVideoCapturer();
+  video_capturer_ = rwhv->CreateVideoCapturer();
   video_capturer_->SetResolutionConstraints(size, size, true);
   video_capturer_->SetAutoThrottlingEnabled(false);
   video_capturer_->SetMinSizeChangePeriod(base::TimeDelta());

shell/browser/osr/osr_render_widget_host_view.cc

@@ -562,10 +562,8 @@ OffScreenRenderWidgetHostView::CreateViewForWidget(
     content::RenderWidgetHost* render_widget_host,
     content::RenderWidgetHost* embedder_render_widget_host,
     content::WebContentsView* web_contents_view) {
-  if (render_widget_host->GetView()) {
-    return static_cast<content::RenderWidgetHostViewBase*>(
-        render_widget_host->GetView());
-  }
+  if (auto* rwhv = render_widget_host->GetView())
+    return static_cast<content::RenderWidgetHostViewBase*>(rwhv);
 
   OffScreenRenderWidgetHostView* embedder_host_view = nullptr;
   if (embedder_render_widget_host) {

shell/browser/osr/osr_web_contents_view.cc

@@ -33,8 +33,8 @@ void OffScreenWebContentsView::SetWebContents(
     content::WebContents* web_contents) {
   web_contents_ = web_contents;
 
-  if (GetView())
-    GetView()->InstallTransparency();
+  if (auto* view = GetView())
+    view->InstallTransparency();
 }
 
 void OffScreenWebContentsView::SetNativeWindow(NativeWindow* window) {
@@ -51,8 +51,8 @@ void OffScreenWebContentsView::SetNativeWindow(NativeWindow* window) {
 
 void OffScreenWebContentsView::OnWindowResize() {
   // In offscreen mode call RenderWidgetHostView's SetSize explicitly
-  if (GetView())
-    GetView()->SetSize(GetSize());
+  if (auto* view = GetView())
+    view->SetSize(GetSize());
 }
 
 void OffScreenWebContentsView::OnWindowClosed() {
@@ -109,7 +109,9 @@ void OffScreenWebContentsView::TransferDragSecurityInfo(WebContentsView* view) {
 }
 
 gfx::Rect OffScreenWebContentsView::GetViewBounds() const {
-  return GetView() ? GetView()->GetViewBounds() : gfx::Rect();
+  if (auto* view = GetView())
+    return view->GetViewBounds();
+  return {};
 }
 
 void OffScreenWebContentsView::CreateView(gfx::NativeView context) {}
@@ -117,10 +119,8 @@ void OffScreenWebContentsView::CreateView(gfx::NativeView context) {}
 content::RenderWidgetHostViewBase*
 OffScreenWebContentsView::CreateViewForWidget(
     content::RenderWidgetHost* render_widget_host) {
-  if (render_widget_host->GetView()) {
-    return static_cast<content::RenderWidgetHostViewBase*>(
-        render_widget_host->GetView());
-  }
+  if (auto* rwhv = render_widget_host->GetView())
+    return static_cast<content::RenderWidgetHostViewBase*>(rwhv);
 
   return new OffScreenRenderWidgetHostView(
       transparent_, painting_, GetFrameRate(), callback_, render_widget_host,
@@ -146,8 +146,8 @@ OffScreenWebContentsView::CreateViewForChildWidget(
 void OffScreenWebContentsView::SetPageTitle(const std::u16string& title) {}
 
 void OffScreenWebContentsView::RenderViewReady() {
-  if (GetView())
-    GetView()->InstallTransparency();
+  if (auto* view = GetView())
+    view->InstallTransparency();
 }
 
 void OffScreenWebContentsView::RenderViewHostChanged(
@@ -183,12 +183,10 @@ void OffScreenWebContentsView::UpdateDragOperation(
     bool document_is_handling_drag) {}
 
 void OffScreenWebContentsView::SetPainting(bool painting) {
-  auto* view = GetView();
   painting_ = painting;
-  if (view != nullptr) {
+  if (auto* view = GetView())
     view->SetPainting(painting);
 }
-}
 
 bool OffScreenWebContentsView::IsPainting() const {
   if (auto* view = GetView())
@@ -197,12 +195,10 @@ bool OffScreenWebContentsView::IsPainting() const {
 }
 
 void OffScreenWebContentsView::SetFrameRate(int frame_rate) {
-  auto* view = GetView();
   frame_rate_ = frame_rate;
-  if (view != nullptr) {
+  if (auto* view = GetView())
     view->SetFrameRate(frame_rate);
 }
-}
 
 int OffScreenWebContentsView::GetFrameRate() const {
   if (auto* view = GetView())

shell/browser/ui/autofill_popup.cc

@@ -192,11 +192,8 @@ void AutofillPopup::CreateView(content::RenderFrameHost* frame_host,
   view_ = new AutofillPopupView(this, parent->GetWidget());
 
   if (offscreen) {
-    auto* rwhv = frame_host->GetView();
-    if (embedder_frame_host != nullptr) {
-      rwhv = embedder_frame_host->GetView();
-    }
-
+    auto* rwhv = embedder_frame_host ? embedder_frame_host->GetView()
+                                     : frame_host->GetView();
     auto* osr_rwhv = static_cast<OffScreenRenderWidgetHostView*>(rwhv);
     view_->view_proxy_ = std::make_unique<OffscreenViewProxy>(view_);
     osr_rwhv->AddViewProxy(view_->view_proxy_.get());