Add RGB565 Texture readback support in gl_helper

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 64edead900919062273824bdf24593f586479459..400fada4bd1b47599e7ba9e3550ed864a40f21d5 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -604,12 +604,23 @@ void RenderWidgetHostViewAndroid::SetBackground(const SkBitmap& background) {
 void RenderWidgetHostViewAndroid::CopyFromCompositingSurface(
     const gfx::Rect& src_subrect,
     const gfx::Size& dst_size,
-    const base::Callback<void(bool, const SkBitmap&)>& callback) {
+    const base::Callback<void(bool, const SkBitmap&)>& callback,
+    bool readback_config_rgb565) {
   if (!using_synchronous_compositor_ && !IsSurfaceAvailableForCopy()) {
     callback.Run(false, SkBitmap());
     return;
   }
-
+  ImageTransportFactoryAndroid* factory =
+      ImageTransportFactoryAndroid::GetInstance();
+  GLHelper* gl_helper = factory->GetGLHelper();
+  if (!gl_helper)
+    return;
+  bool check_rgb565_support = gl_helper->CanUseRgb565Readback();
+  if (readback_config_rgb565 && !check_rgb565_support) {
+    LOG(ERROR) << "Readbackformat rgb565  not supported";
+    callback.Run(false, SkBitmap());
+    return;
+  }
   const gfx::Display& display =
       gfx::Screen::GetNativeScreen()->GetPrimaryDisplay();
   float device_scale_factor = display.device_scale_factor();
@@ -625,7 +636,6 @@ void RenderWidgetHostViewAndroid::CopyFromCompositingSurface(
     SynchronousCopyContents(src_subrect_in_pixel, dst_size_in_pixel, callback);
     return;
   }
-
   scoped_ptr<cc::CopyOutputRequest> request;
   if (src_subrect_in_pixel.size() == dst_size_in_pixel) {
       request = cc::CopyOutputRequest::CreateBitmapRequest(base::Bind(
@@ -636,6 +646,7 @@ void RenderWidgetHostViewAndroid::CopyFromCompositingSurface(
       request = cc::CopyOutputRequest::CreateRequest(base::Bind(
           &RenderWidgetHostViewAndroid::PrepareTextureCopyOutputResult,
           dst_size_in_pixel,
+          readback_config_rgb565,
           callback));
   }
   request->set_area(src_subrect_in_pixel);
@@ -1339,6 +1350,7 @@ void RenderWidgetHostViewAndroid::OnLostResources() {
 // static
 void RenderWidgetHostViewAndroid::PrepareTextureCopyOutputResult(
     const gfx::Size& dst_size_in_pixel,
+    bool readback_config_rgb565,
     const base::Callback<void(bool, const SkBitmap&)>& callback,
     scoped_ptr<cc::CopyOutputResult> result) {
   DCHECK(result->HasTexture());
@@ -1349,8 +1361,12 @@ void RenderWidgetHostViewAndroid::PrepareTextureCopyOutputResult(
     return;
 
   scoped_ptr<SkBitmap> bitmap(new SkBitmap);
-  bitmap->setConfig(SkBitmap::kARGB_8888_Config,
-                    dst_size_in_pixel.width(), dst_size_in_pixel.height(),
+  SkBitmap::Config bitmap_config = readback_config_rgb565 ?
+                                   SkBitmap::kRGB_565_Config :
+                                   SkBitmap::kARGB_8888_Config;
+  bitmap->setConfig(bitmap_config,
+                    dst_size_in_pixel.width(),
+                    dst_size_in_pixel.height(),
                     0, kOpaque_SkAlphaType);
   if (!bitmap->allocPixels())
     return;
@@ -1381,6 +1397,7 @@ void RenderWidgetHostViewAndroid::PrepareTextureCopyOutputResult(
       gfx::Rect(result->size()),
       dst_size_in_pixel,
       pixels,
+      readback_config_rgb565,
       base::Bind(&CopyFromCompositingSurfaceFinished,
                  callback,
                  base::Passed(&release_callback),