Move overscroll effect from the main thread to the compositor thread

Don't handle events on the compositor thread on 10.6 because that platform behaves differently (but still send the flag to Blink saying that overscroll is disabled, even on 10.6, since that will have no effect). BUG=133097 Review URL: https://codereview.chromium.org/831803002 Cr-Commit-Position: refs/heads/master@{#310219}
markYoungH · Jan 7, 2015 · a18c23a · a18c23a
1 parent b2edef9
commit a18c23a
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Showing 5 changed files with 14 additions and 9 deletions.
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
@@ -1339,7 +1339,7 @@ void RenderProcessHostImpl::PropagateBrowserCommandLineToRenderer(
     switches::kEnableSandboxLogging,
 #endif
 #if defined(OS_MACOSX) && !defined(OS_IOS)
-    switches::kEnableThreadedEventHandlingMac,
+    switches::kDisableThreadedEventHandlingMac,
 #endif
 #if defined(OS_WIN)
     switches::kDisableDirectWrite,

diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
@@ -403,8 +403,12 @@ WebPreferences RenderViewHostImpl::ComputeWebkitPrefs(const GURL& url) {
     prefs.pinch_overlay_scrollbar_thickness = 10;
   }
 #if defined(OS_MACOSX)
+  // This preference has the effect of disabling Blink's elastic overscroll,
+  // and may be removed when Blink's elastic overscroll implementation is
+  // removed.
+  // http://crbug.com/138003
   prefs.rubber_banding_on_compositor_thread =
-      command_line.HasSwitch(switches::kEnableThreadedEventHandlingMac);
+      !command_line.HasSwitch(switches::kDisableThreadedEventHandlingMac);
 #endif
   prefs.use_solid_color_scrollbars = ui::IsOverlayScrollbarEnabled();
 

diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
@@ -945,10 +945,11 @@ const char kEnableSpeechDispatcher[] = "enable-speech-dispatcher";
 const char kDisableCoreAnimationPlugins[] =
     "disable-core-animation-plugins";
 
-// Allows input events to be handed on the compositor thread.
-// This feature is under development, see http://crbug.com/138003.
-extern const char kEnableThreadedEventHandlingMac[] =
-    "enable-threaded-event-handling-mac";
+// Force all input events to be handled by Blink on thread. This will be removed
+// once compositor thread events have stuck.
+// http://crbug.com/138003
+extern const char kDisableThreadedEventHandlingMac[] =
+    "disable-threaded-event-handling-mac";
 #endif
 
 #if defined(OS_WIN)

diff --git a/content/public/common/content_switches.h b/content/public/common/content_switches.h
@@ -278,7 +278,7 @@ CONTENT_EXPORT extern const char kEnableSpeechDispatcher[];
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 extern const char kDisableCoreAnimationPlugins[];
-extern const char kEnableThreadedEventHandlingMac[];
+extern const char kDisableThreadedEventHandlingMac[];
 #endif
 
 #if defined(OS_WIN)

diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
@@ -539,8 +539,8 @@ void RenderThreadImpl::Init() {
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   is_elastic_overscroll_enabled_ =
-      base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnableThreadedEventHandlingMac) &&
+      !base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableThreadedEventHandlingMac) &&
       base::mac::IsOSLionOrLater();
 #else
   is_elastic_overscroll_enabled_ = false;