cc: Allow sending BeginMainFrame before draw or activation

cc/base/switches.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/base/switches.h"
 
 #include "base/command_line.h"
 
 namespace cc {
 namespace switches {
@@ skipping 15 matching lines @@
 // Paint content on the main thread instead of the compositor thread.
 // Overrides the kEnableImplSidePainting flag.
 const char kDisableImplSidePainting[] = "disable-impl-side-painting";
 
 // Enables LCD text.
 const char kEnableLCDText[] = "enable-lcd-text";
 
 // Paint content on the compositor thread instead of the main thread.
 const char kEnableImplSidePainting[] = "enable-impl-side-painting";
 
+// Disables the starting the next commit before the previous commit has drawn.
+// Overrides the kEnableStartCommitBeforeDraw flag.
+const char kDisableStartCommitBeforeDraw[] = "disable-start-commit-before-draw";
+
+// Allows the next commit to start before the previous commit has drawn.
+const char kEnableStartCommitBeforeDraw[] = "enable-start-commit-before-draw";
+
+// Disables the starting the next commit before the previous commit activates.
+// Overrides the kEnableStartCommitBeforeDraw flag.
+const char kDisableStartCommitBeforeActivate[] =
+    "disable-start-commit-before-activate";
+
+// Allows the next commit to start before the previous commit activates.
+const char kEnableStartCommitBeforeActivate[] =
+    "enable-start-commit-before-activate";
+
 const char kEnableTopControlsPositionCalculation[] =
     "enable-top-controls-position-calculation";
 
 // Allow heuristics to determine when a layer tile should be drawn with
 // the Skia GPU backend.  Only valid with GPU accelerated compositing +
 // impl-side painting.
 const char kEnableGPURasterization[] = "enable-gpu-rasterization";
 
 // Disable GPU rasterization, i.e. rasterize on the CPU only.
 // Overrides the kEnableGPURasterization flag.
@@ skipping 153 matching lines @@
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
   if (command_line.HasSwitch(switches::kDisableMapImage))
     return false;
   else if (command_line.HasSwitch(switches::kEnableMapImage))
     return true;
 
   return false;
 }
 
+bool IsStartCommitBeforeDrawEnabled() {
+  // Starting the commit before activation implies starting the commit
+  // before draw as well.
+  if (IsStartCommitBeforeActivateEnabled())
+    return true;
+
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+
+  if (command_line.HasSwitch(switches::kDisableStartCommitBeforeDraw))
+    return false;
+  else if (command_line.HasSwitch(switches::kEnableStartCommitBeforeDraw))
+    return true;
+
+  return true;
+}
+
+bool IsStartCommitBeforeActivateEnabled() {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+
+  if (command_line.HasSwitch(switches::kDisableStartCommitBeforeActivate))
+    return false;
+  else if (command_line.HasSwitch(switches::kEnableStartCommitBeforeActivate))
+    return true;
+
+  return false;
+}
+
 }  // namespace switches
 }  // namespace cc