Merge 258167 "android: Readback using delegated rendering layer"

> android: Readback using delegated rendering layer
>
> Using a separate delegated rendering layer for readback allows us to keep the
> readback layer from being displayed. This in turn allows us to clip the content
> layer associated with RWHVAndroid when necessary.
>
> android= https://chrome-internal-review.googlesource.com/157016
> BUG=344720
>
> Review URL: https://codereview.chromium.org/197913002

TBR=powei@chromium.org
BUG=344720

Review URL: https://codereview.chromium.org/208653007

git-svn-id: svn://svn.chromium.org/chrome/branches/1847/src@258878 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 40 insertions, 3 deletions

diff --git a/ui/base/android/window_android.cc b/ui/base/android/window_android.cc
index bacf023..916e821 100644
--- a/ui/base/android/window_android.cc
+++ b/ui/base/android/window_android.cc
@@ -9,6 +9,7 @@
 #include "base/android/jni_helper.h"
 #include "base/android/scoped_java_ref.h"
 #include "jni/WindowAndroid_jni.h"
+#include "ui/base/android/window_android_compositor.h"
 #include "ui/base/android/window_android_observer.h"
 
 namespace ui {
@@ -17,7 +18,8 @@ using base::android::AttachCurrentThread;
 using base::android::ScopedJavaLocalRef;
 
 WindowAndroid::WindowAndroid(JNIEnv* env, jobject obj)
-  : weak_java_window_(env, obj) {
+  : weak_java_window_(env, obj),
+    compositor_(NULL) {
 }
 
 void WindowAndroid::Destroy(JNIEnv* env, jobject obj) {
@@ -66,13 +68,18 @@ void WindowAndroid::RemoveObserver(WindowAndroidObserver* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
-void WindowAndroid::AttachCompositor() {
+void WindowAndroid::AttachCompositor(WindowAndroidCompositor* compositor) {
+  if (compositor_ && compositor != compositor_)
+    DetachCompositor();
+
+  compositor_ = compositor;
   FOR_EACH_OBSERVER(WindowAndroidObserver,
                     observer_list_,
                     OnAttachCompositor());
 }
 
 void WindowAndroid::DetachCompositor() {
+  compositor_ = NULL;
   FOR_EACH_OBSERVER(WindowAndroidObserver,
                     observer_list_,
                     OnDetachCompositor());
diff --git a/ui/base/android/window_android.h b/ui/base/android/window_android.h
index 5e6532e..2563679 100644
--- a/ui/base/android/window_android.h
+++ b/ui/base/android/window_android.h
@@ -15,6 +15,7 @@
 
 namespace ui {
 
+class WindowAndroidCompositor;
 class WindowAndroidObserver;
 
 // Android implementation of the activity window.
@@ -40,17 +41,20 @@ class UI_BASE_EXPORT WindowAndroid {
   // Compositor callback relay.
   void OnCompositingDidCommit();
 
-  void AttachCompositor();
+  void AttachCompositor(WindowAndroidCompositor* compositor);
   void DetachCompositor();
 
   void AddObserver(WindowAndroidObserver* observer);
   void RemoveObserver(WindowAndroidObserver* observer);
 
+  WindowAndroidCompositor* GetCompositor() { return compositor_; }
+
  private:
   ~WindowAndroid();
 
   JavaObjectWeakGlobalRef weak_java_window_;
   gfx::Vector2dF content_offset_;
+  WindowAndroidCompositor* compositor_;
 
   ObserverList<WindowAndroidObserver> observer_list_;
 
diff --git a/ui/base/android/window_android_compositor.h b/ui/base/android/window_android_compositor.h
new file mode 100644
index 0000000..8f219fa
--- /dev/null
+++ b/ui/base/android/window_android_compositor.h
@@ -0,0 +1,26 @@
+// 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.
+
+#ifndef UI_BASE_ANDROID_WINDOW_ANDROID_COMPOSITOR_H_
+#define UI_BASE_ANDROID_WINDOW_ANDROID_COMPOSITOR_H_
+
+#include "ui/base/ui_base_export.h"
+
+namespace cc {
+class Layer;
+}
+
+namespace ui {
+
+// Android interface for compositor-related tasks.
+class UI_BASE_EXPORT WindowAndroidCompositor {
+ public:
+  virtual ~WindowAndroidCompositor() {}
+
+  virtual void AttachLayerForReadback(scoped_refptr<cc::Layer> layer) = 0;
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_ANDROID_WINDOW_ANDROID_COMPOSITOR_H_