Implement screen capture for android

content/browser/media/capture/aura_window_capture_machine.cc

Index: content/browser/media/capture/aura_window_capture_machine.cc
diff --git a/content/browser/media/capture/aura_window_capture_machine.cc b/content/browser/media/capture/aura_window_capture_machine.cc
index d398c6d756b86feb5baf7dc12e67eb36c9265ddb..f8cd0e7c88974e2bde62930d1d47549dc024437c 100644
--- a/content/browser/media/capture/aura_window_capture_machine.cc
+++ b/content/browser/media/capture/aura_window_capture_machine.cc
@@ -117,11 +117,25 @@ AuraWindowCaptureMachine::AuraWindowCaptureMachine()
 
 AuraWindowCaptureMachine::~AuraWindowCaptureMachine() {}
 
-bool AuraWindowCaptureMachine::Start(
+void AuraWindowCaptureMachine::Start(
+    const scoped_refptr<ThreadSafeCaptureOracle>& oracle_proxy,
+    const media::VideoCaptureParams& params,
+    const base::Callback<void(bool)> callback) {
+  // Starts the capture machine asynchronously.
+  BrowserThread::PostTaskAndReplyWithResult(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&AuraWindowCaptureMachine::InternalStart,
+                 base::Unretained(this),
+                 oracle_proxy,
+                 params),
+      callback);
+}
+
+bool AuraWindowCaptureMachine::InternalStart(
     const scoped_refptr<ThreadSafeCaptureOracle>& oracle_proxy,
     const media::VideoCaptureParams& params) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-
   // The window might be destroyed between SetWindow() and Start().
   if (!desktop_window_)
     return false;
@@ -157,6 +171,15 @@ bool AuraWindowCaptureMachine::Start(
 }
 
 void AuraWindowCaptureMachine::Stop(const base::Closure& callback) {
+  // Stops the capture machine asynchronously.
+  BrowserThread::PostTask(

[whywhat, 2015/08/17 13:58:46]

This refactoring (changing a sync method to async) seems like something that
could be done in a separate change for easier reviewing?

+      BrowserThread::UI, FROM_HERE, base::Bind(
+          &AuraWindowCaptureMachine::InternalStop,
+          base::Unretained(this),
+          callback));
+}
+
+void AuraWindowCaptureMachine::InternalStop(const base::Closure& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   power_save_blocker_.reset();