Implement cache clearing API 2/2

Both WebView's and Chrome's cache clearing APIs do the following:
1) Clear the GL shader cache, which corresponds to DATA_TYPE_CACHE in
the language of browser_data_remover.h.
2) Clear the Blink cache of the renderers.

This CL implements the second part.

Change-Id: I2c85de5ca6d286c22954c56a838e4b02cd57b5ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893251Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: Pavel Shmakov <pshmakov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712648}

weblayer/BUILD.gn

@@ -122,6 +122,7 @@ jumbo_static_library("weblayer_lib") {
     "//components/security_interstitials/content:security_interstitial_page",
     "//components/security_interstitials/content/renderer:security_interstitial_page_controller",
     "//components/security_interstitials/core",
+    "//components/web_cache/browser",
     "//content:resources",
     "//content/app/resources",
     "//content/public/app:both",

weblayer/browser/DEPS

@@ -4,6 +4,7 @@ include_rules = [
   "+components/embedder_support",
   "+components/safe_browsing",
   "+components/security_interstitials",
+  "+components/web_cache/browser",
   "+content/public",
   "+mojo/public",
   "+net",

weblayer/browser/profile_impl.cc

@@ -7,6 +7,7 @@
 #include "base/bind.h"
 #include "base/callback_forward.h"
 #include "build/build_config.h"
+#include "components/web_cache/browser/web_cache_manager.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browsing_data_remover.h"
 #include "content/public/browser/download_manager_delegate.h"
@@ -192,6 +193,10 @@ class ProfileImpl::DataClearer : public content::BrowsingDataRemover::Observer {
 };
 
 ProfileImpl::ProfileImpl(const base::FilePath& path) : path_(path) {
+  // Ensure WebCacheManager is created so that it starts observing
+  // OnRenderProcessHostCreated events.
+  web_cache::WebCacheManager::GetInstance();
+
   browser_context_ = std::make_unique<BrowserContextImpl>(path_);
 }
 
@@ -225,6 +230,7 @@ void ProfileImpl::ClearBrowsingData(
         break;
       case BrowsingDataType::CACHE:
         remove_mask |= content::BrowsingDataRemover::DATA_TYPE_CACHE;
+        ClearRendererCache();
         break;
       default:
         NOTREACHED();
@@ -233,6 +239,19 @@ void ProfileImpl::ClearBrowsingData(
   clearer->ClearData(remove_mask, from_time, to_time);
 }
 
+void ProfileImpl::ClearRendererCache() {
+  for (content::RenderProcessHost::iterator iter =
+           content::RenderProcessHost::AllHostsIterator();
+       !iter.IsAtEnd(); iter.Advance()) {
+    content::RenderProcessHost* render_process_host = iter.GetCurrentValue();
+    if (render_process_host->GetBrowserContext() == browser_context_.get() &&
+        render_process_host->IsInitializedAndNotDead()) {
+      web_cache::WebCacheManager::GetInstance()->ClearCacheForProcess(
+          render_process_host->GetID());
+    }
+  }
+}
+
 std::unique_ptr<Profile> Profile::Create(const base::FilePath& path) {
   return std::make_unique<ProfileImpl>(path);
 }

weblayer/browser/profile_impl.h

@@ -49,6 +49,8 @@ class ProfileImpl : public Profile {
   class BrowserContextImpl;
   class DataClearer;
 
+  void ClearRendererCache();
+
   base::FilePath path_;
   std::unique_ptr<BrowserContextImpl> browser_context_;