Don't share renderers between unrelated tabs on Android.

content/browser/renderer_host/render_process_host_unittest.cc

 // Copyright 2013 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 <limits>
+
+#include "content/public/common/content_constants.h"
 #include "content/public/test/mock_render_process_host.h"
 #include "content/test/test_render_view_host.h"
 
 namespace content {
 
 class RenderProcessHostUnitTest : public RenderViewHostTestHarness {};
 
 // Tests that guest RenderProcessHosts are not considered suitable hosts when
 // searching for RenderProcessHost.
 TEST_F(RenderProcessHostUnitTest, GuestsAreNotSuitableHosts) {
   GURL test_url("http://foo.com");
 
   MockRenderProcessHost guest_host(browser_context());
   guest_host.set_is_isolated_guest(true);
 
   EXPECT_FALSE(RenderProcessHostImpl::IsSuitableHost(
       &guest_host, browser_context(), test_url));
   EXPECT_TRUE(RenderProcessHostImpl::IsSuitableHost(
       process(), browser_context(), test_url));
   EXPECT_EQ(
       process(),
       RenderProcessHost::GetExistingProcessHost(browser_context(), test_url));
 }
 
+#if !defined(OS_ANDROID)
+TEST_F(RenderProcessHostUnitTest, RendererProcessLimit) {
+  // Disable any overrides.
+  RenderProcessHostImpl::SetMaxRendererProcessCount(0);
+
+  // Verify that the limit is between 1 and kMaxRendererProcessCount.
+  EXPECT_GT(RenderProcessHostImpl::GetMaxRendererProcessCount(), 0u);
+  EXPECT_LE(RenderProcessHostImpl::GetMaxRendererProcessCount(),
+      kMaxRendererProcessCount);
+
+  // Add dummy process hosts to saturate the limit.
+  ASSERT_NE(0u, kMaxRendererProcessCount);
+  ScopedVector<MockRenderProcessHost> hosts;
+  for (size_t i = 0; i < kMaxRendererProcessCount; ++i) {
+    hosts.push_back(new MockRenderProcessHost(browser_context()));
+  }
+
+  // Verify that the renderer sharing will happen.
+  GURL test_url("http://foo.com");
+  EXPECT_TRUE(RenderProcessHostImpl::ShouldTryToUseExistingProcessHost(
+        browser_context(), test_url));
+}
+#endif
+
+#if defined(OS_ANDROID)
+TEST_F(RenderProcessHostUnitTest, NoRendererProcessLimitOnAndroid) {
+  // Disable any overrides.
+  RenderProcessHostImpl::SetMaxRendererProcessCount(0);
+
+  // Verify that by default the limit on Android returns max size_t.
+  EXPECT_EQ(std::numeric_limits<size_t>::max(),
+      RenderProcessHostImpl::GetMaxRendererProcessCount());
+
+  // Add a few dummy process hosts.
+  ASSERT_NE(0u, kMaxRendererProcessCount);
+  ScopedVector<MockRenderProcessHost> hosts;
+  for (size_t i = 0; i < kMaxRendererProcessCount; ++i) {
+    hosts.push_back(new MockRenderProcessHost(browser_context()));
+  }
+
+  // Verify that the renderer sharing still won't happen.
+  GURL test_url("http://foo.com");
+  EXPECT_FALSE(RenderProcessHostImpl::ShouldTryToUseExistingProcessHost(
+        browser_context(), test_url));
+}
+#endif
+
 }  // namespace content