Start renderer in ContentViewCoreImpl::EvaluateJavaScript.

content/browser/android/content_view_core_impl.cc

Index: content/browser/android/content_view_core_impl.cc
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index 80fe628dd022781a85a0bd56fe22b32d2d270490..78c151291b980d3d098000cc16ed8cb03d4361ba 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -1472,14 +1472,26 @@ void JavaScriptResultCallback(const ScopedJavaGlobalRef<jobject>& callback,
 void ContentViewCoreImpl::EvaluateJavaScript(JNIEnv* env,
                                              jobject obj,
                                              jstring script,
-                                             jobject callback) {
-  RenderViewHost* host = web_contents_->GetRenderViewHost();
-  DCHECK(host);
+                                             jobject callback,
+                                             jboolean start_renderer) {
+  RenderViewHost* rvh =
+      static_cast<RenderViewHost*>(web_contents_->GetRenderViewHost());
+  DCHECK(rvh);
+
+  WebContentsImpl* web_contents_impl =
+      static_cast<WebContentsImpl*>(web_contents_);

[joth, 2013/08/20 05:00:44]

just use web_contents_  -- it's already of type WebContentsImpl*

[michaelbai, 2013/08/20 19:15:20]

Done.

+  if (start_renderer && !rvh->IsRenderViewLive()) {
+    if (!web_contents_impl->CreateRenderView(rvh, MSG_ROUTING_NONE, -1)) {

[joth, 2013/08/20 05:00:44]

this looks kind of complex, and the change in WebContentsImpl I don't really
understand.

would it work to call CreateSwappedOutRenderView() here? This would give almost
the same callpath, but the RenderViewHostManager would then also be involved.
(It sounds like it should be in the know about this)

[michaelbai, 2013/08/20 19:15:20]

Tried, it didn't work, it seemed that a swapped out RenderView was created, the
JavaScript wasn't sent to this RenderView until it becomes the current one, in
order to make it current, it need to navigate to something, which doesn't meet
our requirement that JavaScript needs executed before a page been loading.

Basically, we need a way to start the RenderView without a navigation entry.

On 2013/08/20 05:00:44, joth wrote:

+      LOG(ERROR) <<
+          "Falied to create RenderView in EvaluateJavaScript";
+      return;
+    }
+  }
 
   if (!callback) {
     // No callback requested.
-    host->ExecuteJavascriptInWebFrame(string16(),  // frame_xpath
-                                      ConvertJavaStringToUTF16(env, script));
+    rvh->ExecuteJavascriptInWebFrame(string16(),  // frame_xpath
+                                     ConvertJavaStringToUTF16(env, script));
     return;
   }
 
@@ -1490,7 +1502,7 @@ void ContentViewCoreImpl::EvaluateJavaScript(JNIEnv* env,
   content::RenderViewHost::JavascriptResultCallback c_callback =
       base::Bind(&JavaScriptResultCallback, j_callback);
 
-  host->ExecuteJavascriptInWebFrameCallbackResult(
+  rvh->ExecuteJavascriptInWebFrameCallbackResult(
       string16(),  // frame_xpath
       ConvertJavaStringToUTF16(env, script),
       c_callback);