[Android WebView] Turn on accelerated canvas based on View.isHardwareAccelerated

android_webview/common/aw_switches.h

 // Copyright 2013 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.
 
 #ifndef ANDROID_WEBVIEW_COMMON_AW_SWITCHES_H_
 #define ANDROID_WEBVIEW_COMMON_AW_SWITCHES_H_
 
 namespace switches {
 
 // When set, falls back to using the old disk cache.
 extern const char kDisableSimpleCache[];
 
 // When set, forces use of fallback SW path even on HW canvas.
 extern const char kDisableWebViewGLMode[];
 
 // Used to make tile memory allocation decision. Roughly the number of
 // displays that a single layer will have enough memory for.
 extern const char kTileMemoryMultiplier[];
 
 // Maximum number of gralloc allocations per webview.
 extern const char kNumGrallocBuffersPerWebview[];
 
+// Explicitly enable accelerated 2d canvas.
+// TODO(boliu): Remove this switch once on by default.
+extern const char kEnableAccelerated2dCanvas[];
+
 }  // namespace switches
 
 #endif  // ANDROID_WEBVIEW_COMMON_AW_SWITCHES_H_