Fix UpdateTilePriorities viewport in Android WebView.

android_webview/browser/in_process_view_renderer.cc

 // 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.
 
 #include "android_webview/browser/in_process_view_renderer.h"
 
 #include <android/bitmap.h>
 
 #include "android_webview/browser/aw_gl_surface.h"
 #include "android_webview/browser/scoped_app_gl_state_restore.h"
@@ skipping 369 matching lines @@
   transform.Translate(scroll_at_start_of_frame_.x(),
                       scroll_at_start_of_frame_.y());
   gfx::Rect clip_rect(draw_info->clip_left,
                       draw_info->clip_top,
                       draw_info->clip_right - draw_info->clip_left,
                       draw_info->clip_bottom - draw_info->clip_top);
 
   // Assume we always draw the full visible rect if we are drawing into a layer.
   bool drew_full_visible_rect = true;
 
+  gfx::Rect viewport_rect;
   if (!draw_info->is_layer) {
-    clip_rect.Intersect(cached_global_visible_rect_);
-    drew_full_visible_rect = clip_rect.Contains(cached_global_visible_rect_);
+    viewport_rect = cached_global_visible_rect_;
+    clip_rect.Intersect(viewport_rect);
+    drew_full_visible_rect = clip_rect.Contains(viewport_rect);
+  } else {
+    viewport_rect = clip_rect;
   }
 
   block_invalidates_ = true;
   // TODO(joth): Check return value.
   compositor_->DemandDrawHw(gfx::Size(draw_info->width, draw_info->height),
                             transform,
+                            viewport_rect,
                             clip_rect,
                             state_restore.stencil_enabled());
   block_invalidates_ = false;
   gl_surface_->ResetBackingFrameBufferObject();
 
   EnsureContinuousInvalidation(draw_info, !drew_full_visible_rect);
 }
 
 void InProcessViewRenderer::SetGlobalVisibleRect(
     const gfx::Rect& visible_rect) {
@@ skipping 444 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