Upstream oodles of Chrome for Android code into Chromium.

chrome/browser/android/tab/background_content_view_helper.cc

Index: chrome/browser/android/tab/background_content_view_helper.cc
diff --git a/chrome/browser/android/tab/background_content_view_helper.cc b/chrome/browser/android/tab/background_content_view_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..efb5a244ee9351899e80e31f14e4febec2d0169e
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+++ b/chrome/browser/android/tab/background_content_view_helper.cc
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+// Copyright 2015 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 "chrome/browser/android/tab/background_content_view_helper.h"
+
+#include "base/strings/string_number_conversions.h"
+#include "chrome/browser/android/chrome_web_contents_delegate_android.h"
+#include "chrome/browser/android/tab_android.h"
+#include "chrome/browser/ui/android/window_android_helper.h"
+#include "chrome/browser/ui/tab_helpers.h"
+#include "chrome/common/variations/variations_util.h"
+#include "components/variations/variations_associated_data.h"
+#include "content/public/browser/android/content_view_core.h"
+#include "content/public/browser/web_contents.h"
+#include "jni/BackgroundContentViewHelper_jni.h"
+
+BackgroundContentViewHelper* BackgroundContentViewHelper::FromJavaObject(
+    JNIEnv* env,
+    jobject jobj) {
+  return reinterpret_cast<BackgroundContentViewHelper*>(
+      Java_BackgroundContentViewHelper_getNativePtr(env, jobj));
+}
+
+BackgroundContentViewHelper::BackgroundContentViewHelper() {
+}
+
+BackgroundContentViewHelper::~BackgroundContentViewHelper() {
+}
+
+void BackgroundContentViewHelper::Destroy(JNIEnv* env, jobject jobj) {
+  delete this;
+}
+
+void BackgroundContentViewHelper::SetWebContents(
+    JNIEnv* env,
+    jobject jobj,
+    jobject jcontent_view_core,
+    jobject jweb_contents_delegate) {
+  content::ContentViewCore* content_view_core =
+      content::ContentViewCore::GetNativeContentViewCore(env,
+                                                         jcontent_view_core);
+  DCHECK(content_view_core);
+  DCHECK(content_view_core->GetWebContents());
+
+  web_contents_.reset(content_view_core->GetWebContents());
+  // TODO(ksimbili): Do we actually need tab helpers?
+  TabAndroid::AttachTabHelpers(web_contents_.get());
+  WindowAndroidHelper::FromWebContents(web_contents_.get())->
+      SetWindowAndroid(content_view_core->GetWindowAndroid());
+  web_contents_delegate_.reset(
+      new chrome::android::ChromeWebContentsDelegateAndroid(
+          env, jweb_contents_delegate));
+  web_contents_delegate_->LoadProgressChanged(web_contents_.get(), 0);
+  web_contents_->SetDelegate(web_contents_delegate_.get());
+}
+
+void BackgroundContentViewHelper::ReleaseWebContents(JNIEnv* env,
+                                                     jobject jobj) {
+  DCHECK(web_contents_.get());
+  ignore_result(web_contents_.release());
+}
+
+void BackgroundContentViewHelper::DestroyWebContents(JNIEnv* env,
+                                                     jobject jobj) {
+  DCHECK(web_contents_.get());
+  web_contents_->SetDelegate(NULL);
+  web_contents_.reset();
+  DCHECK(web_contents_delegate_.get());
+  web_contents_delegate_.reset();
+}
+
+void BackgroundContentViewHelper::MergeHistoryFrom(JNIEnv* env,
+                                                   jobject obj,
+                                                   jobject jweb_contents) {
+  if (!web_contents_.get())
+    return;
+  content::WebContents* from_web_contents =
+      content::WebContents::FromJavaWebContents(jweb_contents);
+  DCHECK(from_web_contents);
+
+  if (web_contents_->GetController().CanPruneAllButLastCommitted()) {
+    web_contents_->GetController().CopyStateFromAndPrune(
+        &from_web_contents->GetController(), true);
+  } else {
+    web_contents_->GetController().CopyStateFrom(
+        from_web_contents->GetController());
+  }
+}
+
+namespace {
+
+class OnCloseWebContentsDeleter
+     : public content::WebContentsDelegate,
+       public base::SupportsWeakPtr<OnCloseWebContentsDeleter> {
+  public:
+   explicit OnCloseWebContentsDeleter(content::WebContents* web_contents)
+       : web_contents_(web_contents) {
+     web_contents_->SetDelegate(this);
+     base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
+         base::Bind(&OnCloseWebContentsDeleter::Destroy,
+                    AsWeakPtr()),
+         base::TimeDelta::FromSeconds(kDeleteWithExtremePrejudiceSeconds));
+   }
+
+   void CloseContents(content::WebContents* source) override {
+     DCHECK_EQ(web_contents_, source);
+     Destroy();
+   }
+
+   void SwappedOut(content::WebContents* source) override {
+     DCHECK_EQ(web_contents_, source);
+     Destroy();
+   }
+
+   virtual void Destroy() {
+     delete this;
+   }
+
+  private:
+   static const int kDeleteWithExtremePrejudiceSeconds = 3;
+
+   scoped_ptr<content::WebContents> web_contents_;
+
+   DISALLOW_COPY_AND_ASSIGN(OnCloseWebContentsDeleter);
+ };
+
+}  // namespace
+
+void BackgroundContentViewHelper::UnloadAndDeleteWebContents(
+    JNIEnv* env,
+    jobject jobj,
+    jobject jweb_contents) {
+  content::WebContents* web_contents =
+      content::WebContents::FromJavaWebContents(jweb_contents);
+  if (!web_contents)
+    return;
+  web_contents->DispatchBeforeUnload(false);
+  ignore_result(new OnCloseWebContentsDeleter(web_contents));
+}
+
+int BackgroundContentViewHelper::GetSwapTimeoutMs(JNIEnv* env, jobject jobj) {
+  std::string value = variations::GetVariationParamValue(
+      "InstantSearchClicks", "swap_timeout");
+  int swap_timeout = 0;
+  return (base::StringToInt(value.c_str(), &swap_timeout) ? swap_timeout : 0);
+}
+
+// Returns the minimum number of renderer frames needed before swap is
+// triggered. The default value returned is 2 and is configurable by finch
+// params. The reason for default being 2 is, the background image requests are
+// always issued only after the first non-empty layout(first recalc style) and
+// hence most of the page loads doesn't have background images rendered in their
+// first frame.
+int BackgroundContentViewHelper::GetNumFramesNeededForSwap(JNIEnv* env,
+                                                           jobject jobj) {
+  std::string value = variations::GetVariationParamValue(
+      "InstantSearchClicks", "num_frames_needed_for_swap");
+  int num_frames_needed = 0;
+  return (base::StringToInt(value.c_str(),
+                            &num_frames_needed) ? num_frames_needed : 2);
+}
+
+static jlong Init(JNIEnv* env, jobject obj) {
+  return reinterpret_cast<long>(new BackgroundContentViewHelper());
+}
+
+bool BackgroundContentViewHelper::Register(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}