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Unified Diff: content/browser/renderer_host/render_widget_helper.h

Issue 2702093002: Consistent CopyFromSurface() API, consolidated to RWHV (Closed)
Patch Set: REBASE Created 3 years, 10 months ago
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Index: content/browser/renderer_host/render_widget_helper.h
diff --git a/content/browser/renderer_host/render_widget_helper.h b/content/browser/renderer_host/render_widget_helper.h
index c88ac17e10aa44d1480d72056b86b07c68061698..3e46e2c12169b1755a62bdd9c911e402c740198a 100644
--- a/content/browser/renderer_host/render_widget_helper.h
+++ b/content/browser/renderer_host/render_widget_helper.h
@@ -29,36 +29,6 @@ class SessionStorageNamespace;
// behalf of a RenderWidgetHost. This class bridges between the IO thread
// where the RenderProcessHost's MessageFilter lives and the UI thread where
// the RenderWidgetHost lives.
-//
-//
-// OPTIMIZED TAB SWITCHING
-//
-// When a RenderWidgetHost is in a background tab, it is flagged as hidden.
-// This causes the corresponding RenderWidget to stop sending BackingStore
-// messages. The RenderWidgetHost also discards its backingstore when it is
-// hidden, which helps free up memory. As a result, when a RenderWidgetHost
-// is restored, it can be momentarily be without a backingstore. (Restoring
-// a RenderWidgetHost results in a WasShown message being sent to the
-// RenderWidget, which triggers a full BackingStore message.) This can lead
-// to an observed rendering glitch as the WebContentsImpl will just have to
-// fill white overtop the RenderWidgetHost until the RenderWidgetHost
-// receives a BackingStore message to refresh its backingstore.
-//
-// To avoid this 'white flash', the RenderWidgetHost again makes use of the
-// RenderWidgetHelper's WaitForBackingStoreMsg method. When the
-// RenderWidgetHost's GetBackingStore method is called, it will call
-// WaitForBackingStoreMsg if it has no backingstore.
-//
-// TRANSPORT DIB CREATION
-//
-// On some platforms (currently the Mac) the renderer cannot create transport
-// DIBs because of sandbox limitations. Thus, it has to make synchronous IPCs
-// to the browser for them. Since these requests are synchronous, they cannot
-// terminate on the UI thread. Thus, in this case, this object performs the
-// allocation and maintains the set of allocated transport DIBs which the
-// renderers can refer to.
-//
-
class RenderWidgetHelper
: public base::RefCountedThreadSafe<RenderWidgetHelper,
BrowserThread::DeleteOnIOThread> {
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