| 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.
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| -//
|
| -// 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
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| -// 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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|
|