Tiling priorities in Android Webview.

android_webview/browser/browser_view_renderer.cc

 // Copyright 2014 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 "android_webview/browser/browser_view_renderer.h"
 
 #include "android_webview/browser/browser_view_renderer_client.h"
+#include "android_webview/browser/parent_compositor_draw_constraints.h"
 #include "android_webview/browser/shared_renderer_state.h"
 #include "android_webview/common/aw_switches.h"
 #include "android_webview/public/browser/draw_gl.h"
 #include "base/android/jni_android.h"
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 233 matching lines @@
   ReturnResourceFromParent();
   SynchronousCompositorMemoryPolicy new_policy = CalculateDesiredMemoryPolicy();
   RequestMemoryPolicy(new_policy);
   compositor_->SetMemoryPolicy(memory_policy_);
 
   scoped_ptr<DrawGLInput> draw_gl_input(new DrawGLInput);
   draw_gl_input->scroll_offset = last_on_draw_scroll_offset_;
   draw_gl_input->width = width_;
   draw_gl_input->height = height_;
 
-  gfx::Transform transform;
   gfx::Size surface_size(width_, height_);
   gfx::Rect viewport(surface_size);
-  // TODO(boliu): Should really be |last_on_draw_global_visible_rect_|.
-  // See crbug.com/372073.
   gfx::Rect clip = viewport;
-  scoped_ptr<cc::CompositorFrame> frame = compositor_->DemandDrawHw(
-      surface_size, transform, viewport, clip);
+  gfx::Rect external_tiling_rect;
+  gfx::Transform external_tiling_transform = parent_draw_constraints_.transform;
+  ;
+
+  parent_draw_constraints_ = shared_renderer_state_->ParentDrawConstraints();
+
+  // If the WebView is on a layer, the parent transform is just an identity
+  // matrix and WebView does not know what transform is applied onto the layer.
+  // In this case, just use the surface rect for tiling.
+  if (parent_draw_constraints_.is_layer)
+    external_tiling_rect = parent_draw_constraints_.surface_rect;
+  else
+    external_tiling_rect = last_on_draw_global_visible_rect_;
+
+  scoped_ptr<cc::CompositorFrame> frame =
+      compositor_->DemandDrawHw(surface_size,
+                                gfx::Transform(),
+                                viewport,
+                                clip,
+                                external_tiling_rect,
+                                external_tiling_transform);
   if (!frame.get())
     return false;
 
   GlobalTileManager::GetInstance()->DidUse(tile_manager_key_);
 
   frame->AssignTo(&draw_gl_input->frame);
   ReturnUnusedResource(shared_renderer_state_->PassDrawGLInput());
   shared_renderer_state_->SetDrawGLInput(draw_gl_input.Pass());
   DidComposite();
   return client_->RequestDrawGL(java_canvas, false);
@@ skipping 472 matching lines @@
     base::StringAppendF(&str,
                         "surface width height: [%d %d] ",
                         draw_info->width,
                         draw_info->height);
     base::StringAppendF(&str, "is_layer: %d ", draw_info->is_layer);
   }
   return str;
 }
 
 }  // namespace android_webview